Serious problem with RMI on jdk15

[Greg Lewis]

On Mon, Oct 13, 2008 at 05:58:58PM +0300, Nikolay Denev wrote:
> On Oct 13, 2008, at 5:47 PM, Nikolay Denev wrote:
> > On Oct 9, 2008, at 4:35 PM, Nikolay Denev wrote:
> >
> >> Hi All,
> >>
> >> I have the following problem : when I connect to a jmxremote  
> >> enabled application with jconsole the whole VM crashes with  
> >> segmentation fault.
> >>
> > [...snip...]
> >>
> >> I'm running amd64 7.1-PRE from yesterday, and the jdk is  
> >> jdk-1.5.0.14p8_3,1
> >>
> >> Any help is greatly appreciated!
> >>
> >> Thanks,
> >> Nikolay Denev
> >
> > I think I've tracked down the problem.
> > The JVM crashes when one requests the TotalPhysicalMemory from the  
> > OperatingSystem bean.
> > The strange thing is that Sun specifies this value as "long", but  
> > how this can work on 64bit machines with many gigabytes of memory?
> >
> > What BSD patchset does is read the hw.physmem sysctl, which returns  
> > unsigned long, and then cast it to jlong and probably this is where  
> > the problem is.
> > I've tried disabling the sysctl and hardcoding the result and my JVM  
> > does not crash anymore.
> > Jconsole still does not show anything though.... and the same test  
> > program produces info when used with the diablo-jdk15...
> >
> >
> > Regards,
> > Nikolay Denev
> 
> As I read this now, It's not exactly correct, longs should be 4 bytes  
> on 32bit archs, and 8bytes on 64bit archs.
> So the storage type for TotalPhysicalMemory should be ok. Maybe jlong  
> is not correctly adjusted to 8bytes on 64bit architectures?

A jlong is typedef'ed as a 'long long' on both 32 and 64 bit architectures.
How much memory does the machine have and what architecture is it?

-- 
Greg Lewis                          Email   : glewis at eyesbeyond.com
Eyes Beyond                         Web     : http://www.eyesbeyond.com
Information Technology              FreeBSD : glewis at FreeBSD.org